[media] drxk_hard: fix sparse warnings

drivers/media/dvb-frontends/drxk_hard.c:1086:62: warning: Using plain integer as NULL pointer
drivers/media/dvb-frontends/drxk_hard.c:2784:63: warning: Using plain integer as NULL pointer

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Antti Palosaari <crope@iki.fi>
Reviewed-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
diff --git a/drivers/media/dvb-frontends/drxk_hard.c b/drivers/media/dvb-frontends/drxk_hard.c
index 082014d..d416c15 100644
--- a/drivers/media/dvb-frontends/drxk_hard.c
+++ b/drivers/media/dvb-frontends/drxk_hard.c
@@ -1083,7 +1083,7 @@
 			 SIO_HI_RA_RAM_PAR_1_PAR1_SEC_KEY);
 	if (status < 0)
 		goto error;
-	status = hi_command(state, SIO_HI_RA_RAM_CMD_CONFIG, 0);
+	status = hi_command(state, SIO_HI_RA_RAM_CMD_CONFIG, NULL);
 	if (status < 0)
 		goto error;
 
@@ -2781,7 +2781,7 @@
 			goto error;
 	}
 
-	status = hi_command(state, SIO_HI_RA_RAM_CMD_BRDCTRL, 0);
+	status = hi_command(state, SIO_HI_RA_RAM_CMD_BRDCTRL, NULL);
 
 error:
 	if (status < 0)